ABSTRACT
Sulforaphane (SFN), a natural anti-tumor compound from cruciferous vegetables, has been reported to induce protective autophagy to cancer cells, which might impair the anti-tumor efficiency of SFN. However, the accurate function and mechanism of SFN inducing autophagy in cancers are still obscure, especially in esophageal squamous cell carcinoma (ESCC), one of malignancies with high incidence in North China. Here, we mainly explored the potential function of autophagy upon SFN treatment in ESCC and molecular mechanism. We demonstrated that SFN could inhibit cell proliferation and induce apoptosis by activating caspase pathway. Moreover, we found activation of NRF2 pathway by SFN was responsible for the induction of autophagy and also a disadvantage element to the anti-tumor effects of SFN on ESCC, indicating that SFN might induce protective autophagy in ESCC. We, therefore, investigated effects of autophagy inhibition on sensitivity of ESCC cells to SFN and found that chloroquine (CQ) could neutralize the activation of SFN on NRF2 and enhance the activation of SFN on caspase pathway, thus improved the anti-tumor efficiency of SFN on ESCC
ABSTRACT
Dysregulation of mTORC1/mTORC2 pathway is observed in many cancers and mTORC1 inhibitors have been used clinically in many tumor types; however, the mechanism of mTORC2 in tumorigenesis is still obscure. Here, we mainly explored the potential role of mTORC2 in esophageal squamous cell carcinoma (ESCC) and its effects on the sensitivity of cells to mTOR inhibitors. We demonstrated that RICTOR, the key factor of mTORC2, and p-AKT (Ser473) were excessively activated in ESCC and their overexpression is related to lymph node metastasis and the tumor-node-metastasis (TNM) phase of ESCC patients. Furthermore, we found that mTORC1/ mTORC2 inhibitor PP242 exhibited more efficacious anti-proliferative effect on ESCC cells than mTORC1 inhibitor RAD001 due to RAD001-triggered feedback activation of AKT signal. Another, we demonstrated that down-regulating expression of RICTOR in ECa109 and EC9706 cells inhibited proliferation and migration as well as induced cell cycle arrest and apoptosis. Noteworthy, knocking-down stably RICTOR significantly suppresses RAD001-induced feedback activation of AKT/PRAS40 signaling, and enhances inhibition efficacy of PP242 on the phosphorylation of AKT and PRAS40, thus potentiates the antitumor effect of RAD001 and PP242 both and . Our findings highlight that selective targeting mTORC2 could be a promising therapeutic strategy for future treatment of ESCC.
ABSTRACT
Objective: To investigate the effect of silencing rapamycin insensitive companion of mammalian target of rapamycin (RICTOR) gene expression on the sensitivity of esophageal squamous cell carcinoma cells to everolimus, and to explore its possible molecular mechanism. Methods: The expression level of RICTOR protein in esophageal squamous cell carcinoma TE1, ECa109, EC9706, KYSE450 and KYSE790 cells were detected by Western blotting. RICTOR-shRNA or the Control-shRNA was transfected into ECa109 cells by LipofectAMINE, and the ECa109 cells stably expressing RICTOR-shRNA or the Control-shRNA were screened and named as ECa 109-RICTOR-shRNA or ECa109-control-shRNA cells. The effect of everolimus on the proliferation of ECa109-RICTOR-shRNA cells was detected by CCK-8 assay. The expression levels of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (PKB, Akt)/mammalian target of rapamycin (mTOR) signal pathwayrelated RICTOR, Akt, phospho-Akt (p-Akt) (Ser473), ribosome protein subunit 6 kinase of 70 kDa (p70S6K), phospho-p70S6K (p-p70S6K), proline-rich Akt substrate of 40 kDa (PRAS40) and phospho-PRAS40 (p-PRAS40) (Thr246) proteins in everolimus-treated ECa109-control-shRNA and ECa109-RICTOR-shRNA cells were detected by Western blotting. The nude mouse xenograft tumor models of ECa1 09-RICTOR-shRNA and ECa109-control-shRNA cells were established and treated with everolimus, then the effect of everolimus on tumor growth in nude mice was evaluated. Results: RICTOR protein was expressed in five esophageal squamous cell carcinoma cell lines, especially in ECa1 09 cells. Compared with the Control-shRNA, RICTOR-shRNA inhibited the proliferation of ECa1 09 cells. Everolimus inhibited the proliferation of ECa1 09-RICTOR-shRNA and ECa109-control-shRNA cells, especially to the former; the values of half maximal inhibitory concentration (IC50) were (17.68± 1.25) μmol/L and (36.84±1.57) μmol/L, respectively. The RICTOR-shRNA decreased the expression levels of p-Akt (Ser473) and p-PRAS40 (Thr246) (both P 0.05), which indicated that RICTOR-shRNA inhibited the phosphorylated activation of Akt and PRAS40 induced by everolimus. Both RICTOR-shRNA and everolimus inhibited the growth of ECa109 cell xenografts in nude mice (all P < 0.05), while the inhibitory effect was strongest in RICTOR-shRNA+everolimus group (P < 0.001). Conclusion: Silencing RICTOR gene can improve the sensitivity of esophageal squamous cell carcinoma cells to everolimus, and the molecular mechanism may be associated with the down-regulation of RICTOR expression to inhibit the phosphorylated activation of Akt and PRAS40 induced by everolimus.
ABSTRACT
Objective To analyze the impact of uterine septum on pregnancy and influencing factors on postopera-tive pregnancy. Methods 125 patients with septate uterus and bearing requirement who underwent TCRS were fol-lowed up to assess fertility outcome. The clinical data was retrospectively analyzed. Results Spontaneous abortion rate was 70.40%and 19.39%, live birth rates was 10.40%and 72.45 %in preoperation and postoperation respec-tively. The difference was statistically significant ( < 0.05). Spontaneous abortion rate in older than 35 years old group was significantly higher than that in younger than 35 years old group, but live birth rate was lower. There was no significant difference in different times of operation in uterine cavity, number of abortion and septum length and so on. Conclusions TCRS can significantly improve pregnancy outcome. The age has influence on postoperative pregnancy outcome. Abortion numbers, septum length, septal base width, intrauterine device (IUD) and hormone re-placement therapy (HRT) may have no effects.
ABSTRACT
<p><b>OBJECTIVE</b>To explore the differences in sensitivity to rapamycin of five esophageal squamous cell carcinoma cell lines with different differentiation and the changes of sensitivity of the cells after siRNA-interfered expression of p70S6K.</p><p><b>METHODS</b>Effects of rapamycin on proliferation of ESCC cell lines with different differentiation, EC9706, TE-1, Eca109, KYSE790 and KYSE450 cells, were investigated using cell counting kit 8 (CCK-8) assay, and according to the above results, the EC9706 cells non-sensitive to rapamycin were chosen to be transfected with p70S6K-siRNA. The changes in sensitivity of cells to rapamycin were measured in vitro and in vivo using CCK-8 kit, flow cytometry and tumor formation in nude mice.</p><p><b>RESULTS</b>CCK-8 results showed that all the five cell line cells were sensitive to low concentration of rapamycin (<100 nmol/L), but TE-1 and EC9706 cells, which were with poor differentiation, showed resistance to high concentration of rapamycin. After EC9706 cells were treated with 50, 100, 200, 500 and 1 000 nmol/L rapamycin and p70S6K-siRNA, the proliferation rates of EC9706 cells were (48.67 ± 1.68)%, (15.45 ± 1.54)%, (14.00 ± 0.91)%, (10.97 ± 0.72)% and (2.70 ± 0.32)%, respectively, and were significantly lower than that of cells treated with 50, 100, 200, 500 and 1 000 nmol/L rapamycin and control siRNA [(74.53 ± 1.71)%, (68.27 ± 1.35)%, (71.74 ± 2.44)%, (76.23 ± 1.02)% and (80.21 ± 2.77)%] (P<0.05 for all). The results of flow cytometry showed that the ratios of cells in G1 phase of the p70S6K-siRNA, rapamycin and p70S6K-siRNA+ rapamycin groups were (53.82 ± 1.78)%, (57.87 ± 4.01)% and (73.73 ± 3.68)%, respectively, significantly higher than that in the control group (46.09 ± 2.31)% (P<0.05 for all). The results of tumor formation test in vivo showed that the inhibitory effect of rapamycin on tumor growth was stronger after the cells were transfected with p70S6K-siRNA, and the inhibition rate was 96.5%.</p><p><b>CONCLUSION</b>ESCC cells with different differentiation have different sensitivity to rapamycin, and p70S6K-siRNA can improve the sensitivity of cells to rapamycin in vitro and in vivo.</p>